1. Field of the Invention
This invention relates to methods of reducing the cycle time of producing silicone foams by decreasing the time it takes to post cure the foams. More particularly, this invention relates to methods of reducing the cycle time by using a polyol in the silicone foam composition, increasing the post cure temperature and reducing the post cure time. This invention also relates to methods of producing self- releasing silicone foams.
2. Description of the Related Art
In U.S. Pat. No. 4, 590,222, issued May 20, 1986, Bauman teaches a silicone foam composition containing a polydiorganosiloxane, a resinous copolymer, a platinum catalyst, an organohydrogensiloxane, a hydroxyl-endblocked polydiorganosiloxane, a filler and an organic alcohol.
In European Patent Application No. 661,337 A1, published on Jul. 5, 1995, Takanashi teaches a foamable composition comprising a phenol-containing polyorganosiloxane, a polyorganohydrogen-siloxane, a platinum catalyst, and a monohydric or polyhydric alcohol.
In U.S. Pat. No. 4,871,781, issued on Oct. 3, 1989, Weise teaches a foamable composition comprising a polyorganosiloxane, a polyorganohydrogensiloxane, a platinum catalyst, and a saturated polyhydric alcohol.
In U.S. Pat. No. 5,358,975, issued on Oct. 25, 1994, Anderson teaches a foamable composition comprising a polyorganosiloxane, an organohydrogensiloxane, a platinum catalyst, an .alpha.,w-diol, and a resinous copolymer.
The present inventors discovered that the cycle time of producing a cured silicone foam can be reduced by curing a foam composition containing a polyol on a plastic substrate and post curing the cured foam at an elevated temperature. When the post cure temperature is elevated, the post cure time can be reduced. Foamable compositions that were post cured at elevated temperature and did not contain a polyol, adhered to the plastic substrate.